---
tool_name: image-upscale
summary: Real-ESRGAN 4x super-resolution — make small images print-ready without the mush.
input:
  file: binary, required # image to upscale (max 20MB)
  scale: enum, required # 放大倍数
output:
  preview_url: string | watermarked preview, free, no auth
  task_id: string | unique task identifier
  payment_url: string | end-user must complete one-time payment to unlock final output
  final_download_url: string | only available after successful payment
auth: login via email/phone OTP on https://image-upscale.yeezhan.com; API callers use a personal API key (Bearer yeek_...)
payment_rule: one-time charge $2.99 per task. NO credits, NO account balance. One payment unlocks only this task.
valid_window: 24 hours after payment
errors:
  - file_too_large
  - invalid_input
  - unsupported_type
  - target_unreachable
  - processing_failed
endpoint: https://image-upscale.yeezhan.com/api/v1/run
---